{"product_id":"square-d-lja36400u31x-powerpact-lj-400-circuit-breaker-400a","title":"Square D LJA36400U31X Powerpact LJ 400 Circuit Breaker 400A","description":"\u003cdiv\u003e\n\u003cp\u003e\u003cstrong\u003eSquare D LJA36400U31X Powerpact LJ 400 Circuit Breaker\u003c\/strong\u003e is a trusted 400A solution designed to power demanding electrical environments with stability and clarity. Built by Square D, this LJ-series breaker is engineered for predictable protection, fast fault isolation, and long-term reliability in industrial, commercial, and high-demand residential applications.\u003c\/p\u003e \u003cp\u003eDesigned for panel upgrades, retrofit projects, and maintenance replacement work where dependable performance matters, this unit is a smart choice for professionals who need components they can count on. The LJA36400U31X brings consistency to service work, panel builds, and spare-stock inventories, helping you reduce downtime and keep projects on schedule.\u003c\/p\u003e \u003ch3\u003eWhy this Powerpact LJ 400A matters\u003c\/h3\u003e\n\u003cul\u003e \u003cli\u003e\n\u003cstrong\u003eAmperage and capacity:\u003c\/strong\u003e 400A rating with space for up to 400 circuits, making it suitable for large distribution panels and high-demand installations.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eIndustry-ready reliability:\u003c\/strong\u003e Square D’s Powerpact LJ design is built for robust performance in environments where uptime is critical.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eVersatile deployment:\u003c\/strong\u003e Ideal for industrial facilities, commercial buildings, and demanding residential projects that require strong, standardized protection components.\u003c\/li\u003e \u003cli\u003e\n\u003cstrong\u003eProfessional-grade fit:\u003c\/strong\u003e A dependable option for electricians, panel builders, and MRO teams who need trusted parts for service work and routine replacements.\u003c\/li\u003e\n\u003c\/ul\u003e \u003cp\u003e\u003cstrong\u003eKey use cases\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e \u003cli\u003ePanel upgrades: modernize distribution with a reliable 400A protection solution designed for high circuit density.\u003c\/li\u003e \u003cli\u003eRetrofit projects: replace aging breakers with a proven Powerpact LJ unit to maintain system protection and compatibility.\u003c\/li\u003e \u003cli\u003eMaintenance and service work: stocking spares to minimize downtime during outages or routine maintenance.\u003c\/li\u003e\n\u003c\/ul\u003e \u003cp\u003e\u003cstrong\u003ePractical tips for deployment\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e \u003cli\u003eConfirm panel compatibility with Powerpact LJ breakers in the existing distribution system to ensure a seamless fit and protection coordination.\u003c\/li\u003e \u003cli\u003eKeep a spare LJA36400U31X on hand for proactive maintenance and fast replacements, helping you avoid extended outages.\u003c\/li\u003e \u003cli\u003eDocument the amperage and circuit capacity in your panel plan to optimize fault isolation and load management across the 400-circuit layout.\u003c\/li\u003e\n\u003c\/ul\u003e \u003cp\u003eWith the Square D LJA36400U31X Powerpact LJ 400, you’re choosing a proven, scalable protection solution that supports large-panel architectures while delivering dependable performance for everyday service work and critical installations alike.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Square D","offers":[{"title":"Default Title","offer_id":46395819655330,"sku":null,"price":6542.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0666\/8094\/6850\/files\/panelboard_generic.png?v=1762425115","url":"https:\/\/www.ampstate.com\/products\/square-d-lja36400u31x-powerpact-lj-400-circuit-breaker-400a","provider":"Ampstate Electric Corporation","version":"1.0","type":"link"}